Peristaltic air pumping tube and tire assembly and method

Abstract

 A pneumatic tire having a tire cavity (28) defined by an inner liner (26), an air inlet housing (92) affixed to the inner liner (26) and a first sidewall (16) having an elongate sidewall groove (30) therein is disclosed. The elongate sidewall groove (30) contains an elongate air tube (34) having an elongate internal air passageway (32). The air tube (34) is located to operatively compress segment by segment from an expanded diameter to a substantially reduced diameter responsive to a bending strain introduced into the first sidewall (16) from a rolling tire footprint whereby forcing air segment by segment along the air tube internal air passageway (32). The air tube (34) has a substantially on-side mushroom-shaped sectional profile extending radially into the first tire sidewall (16). The air tube (34) has a radially inward cap of relatively larger diametric dimension affixed to a radially outward tube stem of relatively smaller diametric dimension, the inward tube cap residing within an a relatively larger diametric region of the sidewall groove (30) and extending in a lateral outward direction from the tube stem in an orientation substantially parallel with an outward surface of the first sidewall (16). The tube stem has a tapering sectional profile defined by converging sides extending in a radial direction outward from the tube cap to a radially outward stem end surface. Also, a method of assembling a peristaltic air pumping mechanism (14) into a tire (12). The tire (12) is preferably an air maintenance tire.

Description

Field of the invention

[0001] The invention relates generally to pneumatic tires such as air maintenance tires and, more specifically, to such tires having a sidewall-located tubular pump mechanism and tire assembly.

Background of the Invention

[0002] Normal air diffusion reduces tire pressure over time. The natural state of tires is under inflated. Accordingly, drivers must repeatedly act to maintain tire pressures or they will see reduced fuel economy, tire life and reduced vehicle braking and handling performance. Tire Pressure Monitoring Systems have been proposed to warn drivers when tire pressure is significantly low. Such systems, however, remain dependant upon the driver taking remedial action when warned to re-inflate a tire to recommended pressure. It is a desirable, therefore, to incorporate an air maintenance pumping system within a tire that will maintain tire air pressure to compensate for any reduction in tire pressure over time without the need for driver intervention.

Summary of the Invention

[0003] The invention relates to a tire in accordance with claim 1 and to a method in accordance with claim 11.

[0004] Dependent claims refer to preferred embodiments of the invention.

[0005] In a preferred aspect of the invention, an air maintenance tire and method of assembly includes an air inlet housing affixed to the inner liner of a tire. A first tire sidewall has an elongate sidewall groove therein containing an elongate air tube having an elongate elliptical internal air passageway. The air tube is operatively located to compress segment by segment from an expanded diameter to a substantially reduced diameter responsive to a bending strain introduced into the first sidewall from a rolling tire footprint; whereby forcing air segment by segment along the air tube internal air passageway. The air tube is configured having a substantially on-side mushroom-shaped sectional profile extending radially into the first tire sidewall formed from a radially inward tube cap and a radially outward tube stem. The tube stem has a tapering sectional profile defined by converging sides extending in a radial direction outward from the tube cap to a radially outward stem end surface.

[0006] In another preferred aspect, an intake conduit is provided to route air from outside of the tire through the first tire sidewall, to the tire inner liner, and into the inlet housing. The inlet conduit and the intake conduit attach to and detach from respective first and second elongate sockets formed by the inlet housing.

[0007] In yet a further aspect, a pressure regulating valve system is housed within the inlet housing for controlling pressurized air flow from the tube internal air passageway into the tire cavity.

Definitions

[0008] 

"Axial" and "axially" means lines or directions that are parallel to the axis of rotation of the tire.

"Circumferential" means lines or directions extending along the perimeter of the surface of the annular tread perpendicular to the axial direction.

"Equatorial Centerplane (CP)" means the plane perpendicular to the tire's axis of rotation and passing through the center of the tread.

"Footprint" means the contact patch or area of contact of the tire tread with a flat surface at zero speed and under normal load and pressure.

"Lateral" means an axial direction.

"Peristaltic" means operating by means of wave-like contractions that propel contained matter, such as air, along tubular pathways.

"Radial" and "radially" means directions radially toward or away from the axis of rotation of the tire.

Brief Description of the Drawings

[0009] The invention will be described by way of example and with reference to the accompanying drawings in which:

FIG. 1 is a quarter section exploded perspective view of a tire showing the inlet, filter, outlet and tube of a two 180 degree (reversible) peristaltic air pump system.

FIG. 2 is a side view of tire showing inlet, outlet and tube locations.

FIG. 3 is a perspective view of tube with inlet and outlet connectors.

FIG. 4A is a perspective view of connector housing from FIG. 3.

FIG. 4B is a section view of connector housing from FIG. 4A.

FIG. 4C is an enlarged view of inlet conduit area from FIG. 4B.

FIG. 5A is a perspective view of filter and intake conduit.

FIG. 5B is a section view of filter and intake conduit from FIG. 6A.

FIG. 5C is an enlarged view of intake conduit area from FIG. 5B.

FIG. 6A is a top perspective view of inlet housing.

FIG. 6B is a bottom perspective view of inlet housing.

FIG. 6C is a partial section view of connection area from FIG. 6A.

FIG. 7A is an enlarged section view of inlet area showing location of filter, inlet conduit, and air tube.

FIG. 7B is an enlarged section view of inlet area showing filter, inlet conduit and air tube in place. The inlet housing and rubber mounting bracket are shown exploded.

FIG. 7C is an enlarged section view of inlet area showing the inlet housing and rubber mounting bracket in relation to the tire.

FIG. 7D is an enlarged section view of inlet area showing rubber mounting bracket installed.

FIG. 8 is a section view of the inlet area.

Detailed Description of the Invention

[0010] Referring to FIGS. 1 through 3, a tire assembly 10 with a tire 10 is shown. The tire 10 comprises a tire-based peristaltic pump assembly 14. The tire 12 preferably mounts in conventional fashion to a rim (not shown) for vehicle use. The tire is preferably of conventional construction, having a pair of sidewalls 16, 18 extending from opposite bead areas 20, 22 to a crown or tire read region 24. The tire 12 and rim enclose a tire cavity 28 that is defined by a tire inner liner 26.

[0011] As seen from FIGS. 1, 2 and 3, the peristaltic pump assembly 14 includes an annular air tube 34 that encloses an annular air passageway 32. The tube 34 is formed of a resilient, flexible material such as plastic or rubber compounds that is capable of withstanding repeated deformation cycles wherein the tube is deformed into a flattened condition subject to external force and, upon removal of such force, returns to an original condition generally circular in cross-section. The tube is of a diameter sufficient to operatively pass a volume of air sufficient for the purposes described herein and allowing a positioning of the tube in an operable location within the tire assembly.

[0012] The operational principle of the peristaltic pumping tube in a tire for the purpose of maintaining tire air pressure is described in issued US-B- 8,113,254. As disclosed, a peristaltic pumping tube is incorporate within a tire sidewall. As disclosed by the above patent a preferably T-shaped inlet device is affixed inline with an annular pumping tube and conducts air from outside of the tire into the pumping tube for pressurization. A preferably T-shaped outlet device, positioned opposite the inlet device, is likewise affixed inline with the pumping tube. The outlet device conducts pressurized air from the pumping tube into the tire cavity to maintain cavity pressure at a desired level. Functionally, the pumping tube is located in a high flex region of the sidewall. So located, the pumping tube compresses segment by segment from an expanded diameter to a substantially reduced diameter responsive to a bending strain introduced into the sidewall from a rolling tire footprint. Pressurized air is thereby forced segment by segment along the air tube and directed as needed into the tire cavity for pressure maintenance.

[0013] While working well, the inlet and outlet devices taught by US-B- 8,113,254 are relatively large and their incorporation into and occupancy within a tire sidewall introduces structural disruption in the sidewall. Moreover, the inlet and outlet devices are difficult to access and repair should that become necessary. Finally, the inlet and outlet devices of the patent are not easily affixed to the pump air tube and replacing such devices within a tire sidewall could prove problematic.

[0014] The peristaltic pump assembly 14 of the subject invention provides a snap-in inlet attachment system for connecting components together. Air from outside the tire is routed by the intake assembly into the tire cavity, and then from the tire cavity into a peristaltic, sidewall based, pumping tube 34. The pumping tube 34 resides within a groove 30 formed within a tire sidewall 16. The invention as seen in FIGS. 1-3 includes a preferably T-inlet portal 36. The air tube 34 is mounted within the profiled sidewall groove 30 formed within the sidewall 16 proximate the bead region 20 of the sidewall. The groove 30 and the tube 34 assembled therein circumscribes a lower sidewall region. The T-inlet portal 36 includes an inlet connector 38. A filter intake component 40 is further optionally provided that brings air from outside the tire through the tire sidewall 16 to the tire inner liner 26 for a purpose explained below.

[0015] Referring to FIGS. 4A, 4B and 4C, at the preferably T-inlet portal 32, the connector 38 is positioned in-line with the air pumping tube 34. The connector 38 has an elongate in-line connector body 44 from which outwardly projecting wing protrusions 46 extend. The in-line body 44 and wing protrusions 46 combine to form a connector of preferably generally T-shape in cross-section. The in-line body 44 of the connector 38 tapers inward from the wing protrusions 46 to an outwardly facing flat surface region 48. A pair of axial chambers 50, 52 reside within the in-line connector body 44 and are connected by a medially located axial passageway 54. Oppositely directed in-line air tube-engaging coupling posts 56, 58 extend from opposite ends of the in-line body 44. The coupling posts 56, 58 have axial passageways 60, 62, respectively, that communicate with respective air chambers 50, 52 within the connector body 44. End regions of the coupling posts 56, 58 are sized to be closely received respectively into opposite ends of the air tube 34 and have a series of annular retention ribs 64 formed to engage the air tube 34 and assist in maintaining the connection between the coupling posts 56, 58 and respective air tube ends.

[0016] A tubular inlet conduit 66 having an axial internal air passageway 68 is connected to the connector body 44. Air flowing through the inlet conduit 66 is routed through the air chambers 50, 52 and the tube-engaging coupling posts 56, 58, and enters the air tube 28. An outward end region 70 of the inlet conduit 66 is configured having an axial series of spaced apart annular snap-in ribs 72. Each annular rib 72 has a frustro-conical profile, tapering toward a remote end of the inlet conduit 66 as best seen in FIG. 4C

[0017] Referring to FIGS. 5A, 5B and 5C, an elongate, cylindrical air intake conduit 76 is integrally coupled with a larger diameter filter seating chamber 74. The chamber 74 is defined by a cylindrical filter housing 78. The housing 78 receives a porous cylindrical filter element 80 therein. The elongate tubular intake conduit 76 has a central axial air passageway 86. Annular retention flanges 82, 84 extend the circumference of the housing 78. A remote coupling end 88 of the intake conduit 76 is provided with a series of frustro-conical annular coupling ribs 90, tapering inward toward a remote end of the conduit 76. The passageway 86 communicates with the outer filter chamber 74 in which the porous filter element 80 is seated The outward filter end of the intake conduit 76 is positioned in communication with air outside of the tire and functions to intake air into the pumping system. The intake conduit 76 routes the outside air to the inner liner region of the tire as will be explained. Accordingly, the axial length of the intake conduit 76 is sufficiently long to span from the filter element 80 through the tire sidewall 16, to the tire inner liner 26. A cap component encloses the filter housing 78 to retain the filter element 80 inside.

[0018] In FIGS. 6A, 6B and 6C, an inlet housing 92 is shown. The housing 92 is of generally a rectangular block configuration having elongate sidewalls 94, 96 and top and bottom walls 98, 100. Other geometries may be employed if desired to configure the housing 92. Extending into the bottom wall 100 are a spaced apart pair of quick-connect inlet sockets 102, 104, integrally formed by the housing 92. The sockets 102, 104 are elongate and of generally cylindrical inward configuration. The sockets 102, 104 create air passageways into an internal inlet housing air chamber (not shown). Positioned along inward lengths of the sockets 102, 104 are a series of annular detents of frustro-conical configuration. An externally accessible pressure setting nut and bolt 108 extends into the housing 92. Along the bottom surface 100 are a series of outwardly projecting ridges 110; the ridges 110 operable to assist in the adherence of an adhesive coating (not shown) that is used to attach the housing 92 to the tire inner liner 26.

[0019] As used herein, "inlet housing" is applied as a generic term in its broadest sense as a housing that receives inlet air. The housing 92 takes air from the intake conduit 76 and delivers it into the air pumping tube 34. The pumping tube 34 in turn pressurizes the air with each full or partial tire revolution. While referred to generically as an "inlet housing", the inlet housing 92 is specifically used in the preferred embodiment as a housing which, in addition to receiving inlet air, contains a valving regulator system of controlling air pressure within the tire cavity 28. When air pressure within the tire cavity 28 is at a threshold pressure, the regulator within housing 92 closes to prevent additional pressurized air from entering the tire cavity.

[0020] When air within the tire cavity 28 is below a threshold level, the regulator within housing 92 opens and pressurized air is admitted into the tire cavity.

[0021] A suitable regulator valve system would typically include a pressure measurement mechanism operable to measure tire cavity air pressure. The measured cavity air pressure then is used to open or close the flow of air into the tire cavity 28 from the air tube 34. A representative suitable two-port valve system useful in the subject air maintenance tire system is found in co-pending U.S. Patent Application Serial No. 14/041490, filed September 30, 2013. In the two-port system disclosed, intake air would be conducted through the intake conduit 76 into the inlet housing 92 by way of socket 102. The inlet air within housing 92 is directed into the pumping tube 34 an air flow path through socket 104 and inlet conduit 66 to inlet connector 38. Air is then pressurized peristaltically by the air tube 34. If air is required to bring the tire cavity pressure up to threshold, the pressurized air is directed into the tire cavity. If the measured cavity pressure is at threshold, the pressurized air from the pumping tube 34 is vented.

[0022] As best seen from FIG. 6C and 8, each of the sockets 102, 104 are integrally formed by the housing 92, and have an elongate cylindrical internal configuration. The air passageways through the sockets 102, 104 communicate with an air chamber within the housing 92. The sockets 102, 104 are further formed by the housing 92 to each have a respective series of spaced apart frustro-conical detents 106 formed in cylindrical sidewalls defining each respective socket. The placement, configuration, and dimension of the detents 106 within sockets 104, 102 are intended to facilitate mating snap-in engagement with the intake conduit annular frustro-conical ribs 90 and the inlet conduit frustro-conical annular ribs 72, respectively. The conduits 70, 88 thus snap-in conveniently and quickly into respective sockets of the regulator housing 92. Replacement or repair of the housing or intake or inlet assemblies is thus expedited should such replacement or repair become necessary. The snap-in assembly further allows for the placement of the regulator assembly against the inside of the tire, affixed to the inner liner 26. The conduits 70, 88 have a shaft length sufficient to span the tire sidewall 16, project through the apertures 130, 128, of the mounting bracket 126, and fully snap-in insert into respective sockets 104, 102 of the inlet housing 92.

[0023] Referring to FIGS. 7A through 7C, assembly of the air tube 34 into the groove 30 of tire sidewall 16 and attachment of the inlet housing 92 to the tire inner liner 26 are shown. The air tube 34 and the inlet connector 38 are each elongate and generally mushroom shaped in cross section. The wing projections 114 of the tube 34 and the wing projections 46 from the connector body 42 retain and seat within respective portions formed by the sidewall groove 30. The mushroom configuration is shown in detail in US-A- 2013/0299055. In the subject "mushroom" configuration, the peristaltic tube 34 includes a truncated wedge-shaped outboard tube body 112 defined by outwardly divergent sides extending from a small width dimensioned (D3) flat end surface 118 to an inboard domed wing protrusions 114, each having an upper arcuate surface of radius R1 and an underside flat surface. The wing protrusions 114 are distanced L4 from the end wall and the tube is dimensioned in transverse section L1. The sides of the wedge shaped body 112 outwardly diverge at an angle α and intersect the wing projection underside surface. The cap region of the tube 34 is flat on the inward end. The air passageway 32 is elliptical and located within the tube body 112, having a major longitudinal axis oriented along a cross-sectional centerline of the tube. The length of the elliptical passageway is L2 and its transverse width is D2. D1 designates the tip to tip span of the tube and D3 the diameter of the narrower end of the tube. L3 is the distance within the tube from the end surface to a center of the elliptical passageway 32.

[0024] The air tube 34 accordingly has preferred dimensions within the ranges specified below:

D1: 6.39 +/- 0.1 mm;

D2: 0.7 +/- 0.01 mm;

D3: 1.44 +/- 0.05 mm;

L1: 4.25 mm;

L2: 2.2 +/- 0.1 mm;

L3: 1.78 +/- 0.01 mm;

L4: 1.83 +/- 0.05 mm;

α: 24 degrees;

R1: 1.85 mm.

[0025] The inlet connector 42 is configured complementary with the air tube 34 and shares the complementarily configured groove 30. As such, the inlet connector 38 is generally elongate and generally mushroom shaped in cross section. The wing protrusions 46 of the connector 38 extend from the inline connector body 42. The body 42 and the wing protrusions 46 of the connector 38 reside within the groove 30 and retain and seat the connector 38 within the groove 30. In the "mushroom" configuration, as with tube 34, the inlet connector 38 includes the truncated wedge-shaped outboard in-line body portion 44 defined by outwardly divergent sides extending from a small width dimensioned (D3) flat end surface 48 to the inboard domed wing protrusions 46. Each wing protrusion 46 has an upper arcuate surface of radius R1 and an underside flat surface. The wing protrusions 46 are distanced L4 from the end wall and the tube is dimensioned in transverse section L1. The sides of the wedge shaped connector body portion 44 outwardly diverge at an angle α and intersect the flat underside surfaces of the wing protrusions 46. The cap region defined by wing protrusions 46 is flat on the inward end. The external dimensions of the mushroom shaped connector 38 are as set forth above for the air tube 34 and complement the dimensions and configuration of the groove 30 within the sidewall 16.

[0026] With reference to FIGS. 7A through 7D, the air tube 34 and inlet connector 38 mount through a narrow entry slit 116 leading to the groove 30. The air tube 34 and inlet connector 38 are compressed resiliently to gain admittance through the slit 116. Upon entering the groove 30, the air tube 34 and inlet connector 38 flex into their respective common mushroom configurations to fill the profile and geometry of the mushroom shaped groove 30. When fully inserted, the flat surface 48 at the tapered end of the inlet connector body portion 44 and the flat end surface 118 at the tapered outer side of the air tube body 112 are generally coplanar with the outer side of tire side wall 16 and fill the opening created by the slit 116. A throughbore 120 is formed through the sidewall 16 and includes an outer larger diameter filter pocket or chamber 124. The throughbore 120 is this configured and dimensioned for close receipt of the filter intake component 40. The intake conduit 76 extends through the throughbore 120 to the tire inner liner 26 side. The filter pocket 124 receives the filter chamber 74 and filter 80.

[0027] A second through bore 122 is created through the tire sidewall 16 by conventional post-cure manufacture procedures. The through bore 122 is sized to accept the cylindrical inlet conduit 66 of inlet connector 42. The inlet connector conduit 66 projects through the through bore 122 to the inner liner 26 side of the tire sidewall 16.

[0028] As seen in FIG. 7B, 7C and 8, the intake conduit 88 and the inlet conduit 70 project a sufficient distance into the tire cavity 28 from the tire inner liner 26 to extend through the respective bracket apertures 130, 128 The bracket 126 is formed of elastomeric material such as rubber compound. The intake conduit 88 and the inlet conduit 70 are then inserted into the sockets 104, 102 of the inlet housing 92 to assemble the inlet housing 92 against the bracket 126 and the tire inner liner 26. A suitable adhesive may be applied to fixedly connect the bracket 126 and the housing 92 to the tire inner liner 26. The close insertion of the shafts from the intake conduit 88 and the inlet connector 60 into respective sockets establishes a snap-fit engagement as annular ribs along the ends of such shafts engage annular detents within the sockets. An air path is thereby established through the intake conduit 88 and into the inlet housing 92 central air chamber; and from the central air chamber of the inlet housing 92 through the inlet connector 38 into the air tube passageway 32. The regulator valve system within the inlet housing 92 is thus connected to control the flow of air into the air tube 34 and control the flow of pressurized air from the air tube into the tire cavity. Air pressure is thus maintained at a desired level within the tire cavity.

[0029] From the above, it will be apparent that the orientation of the mushroom-shaped air tube and the mushroom-shaped inlet connector are in mutual axial alignment and reside end to end within the complementary, on-side mushroom-shaped groove within the tire sidewall 16. The mushroom shaped profile of the air tube and the inlet connector is on-side, with the domed "cap" or wing protrusion side of the mushroom configuration positioned radially inward and on-side toward the tire cavity. The "stem" of the mushroom-shaped air tube and the inlet connector is oriented on-side and extends radially outward from its intersection location with the tube cap. The internal air passageway of the air tube is generally elliptical in cross-section, with a longitudinal axis of the air passageway oriented in an axial direction between the sidewall outer surface and the tire cavity. A transverse short axis of the elliptical passageway extends in a direction parallel with the extension of the air tube cap and the outward surface of the tire sidewall. The elliptical air passageway is located within the air tube at the intersection of the tube stem and cap.

[0030] The cap of the air tube, projecting outward from the stem, has a larger diameter than the stem. The cap thus serves to retain the air tube within the sidewall groove. The air tube is positioned within the tire sidewall at a high flex region. So located, the air tube is operative to compress segment by segment from an expanded diameter to a substantially reduced diameter responsive to a bending strain introduced into the first sidewall from a rolling tire footprint; whereby forcing air segment by segment along the air tube internal air passageway. The air tube is configured having a substantially on-side mushroom-shaped sectional profile extending radially into the first tire sidewall formed by the radially inward tube cap and the radially outward tube stem. The tube stem has a tapering sectional profile defined by converging sides extending in a radial direction outward from the tube cap to a radially outward stem end surface. The stem end surface is located at the groove entrance into the tire sidewall and obstructs the entryway to the groove once the air tube is assembled into the groove.

[0031] The intake conduit provided serves to route air from outside of the tire through the first tire sidewall, to the tire inner liner, and into the inlet housing. The inlet conduit and the intake conduit attach to and detach from respective first and second elongate sockets formed by the inlet housing. A pressure regulating valve system is housed within the inlet housing for controlling pressurized air flow from the tube internal air passageway into the tire cavity.

[0032] Accordingly, the intake conduit and the inlet conduit both project through the tire sidewall 16 to the inner liner mounted inlet housing 92. By situating the inlet housing 92 within the tire cavity and against the tire inner liner, minimal structural disruption of the tire sidewall construction is required. The structural integrity of the tire sidewall is therefore not compromised because the volume occupied by the inlet housing 92 is accommodated by the tire cavity volume rather than the interior of the tire sidewall. The quick connection and disconnect achieved by the attachment of the intake and inlet conduits into inlet housing sockets enables the achievement of an efficient assembly protocol while enabling disassembly in the event that repair or replacement of components becomes necessary.

Claims

1. A pneumatic tire having:

a tire cavity (28) defined by an inner liner (26);

an air inlet housing (92) affixed to the inner liner (26);

a first sidewall (16) having an elongate sidewall groove (30) therein containing an elongate air tube (34) having an elongate internal air passageway (32), wherein the air tube (34) is located to operatively compress segment by segment from an expanded diameter to a substantially reduced diameter responsive to a bending strain introduced into the first sidewall (16) from a rolling tire footprint whereby forcing air segment by segment along the air tube internal air passageway (32);

wherein the air tube (34) has a substantially on-side mushroom-shaped sectional profile extending radially into the first tire sidewall (16), the air tube (34) having a radially inward cap of relatively larger diametric dimension affixed to a radially outward tube stem of relatively smaller diametric dimension, the inward tube cap residing within an a relatively larger diametric region of the sidewall groove (30) and extending in a lateral outward direction from the tube stem in an orientation substantially parallel with an outward surface of the first sidewall (16); and wherein

the tube stem has a tapering sectional profile defined by converging sides extending in a radial direction outward from the tube cap to a radially outward stem end surface.

2. The tire of claim 1, further comprising:

an elongate tubular inlet conduit (66) extending between the air tube (34) and the inlet housing (92), the inlet conduit (66) having an internal air passageway (68) operative to route inlet air from within the inlet housing (92) to the air tube internal air passageway (32); and/or

an air intake conduit (76) extending through the first sidewall (16) to the inner liner (26), the air intake conduit (76) being coupled to the air inlet housing (92) and operative to route air from outside the tire (12) through the first sidewall (16) and into the air inlet housing (92).

3. The tire of claim 2, wherein the inlet conduit (66) and the air intake conduit (76) each engage into respective first and second elongate sockets formed by the inlet housing (92), whereby establishing respective air flow communication into the inlet housing (92).

4. The tire of at least one of the previous claims, wherein the tube stem extends in the radial direction substantially ninety degrees from the tube cap extension.

5. The tire of at least one of the previous claims, wherein the air tube internal air passageway (32) has a substantially elliptical configuration in transverse section, the elliptical configuration having a longitudinal axis extending radially and a transverse axis extending substantially parallel to the outward surface of the first sidewall (16).

6. The tire of at least one of the previous claims, wherein the air tube internal air passageway (32) is positioned within the air tube (34) substantially at an intersection of the tube cap and the tube stem.

7. The tire of at least one of the previous claims, wherein the tube end surface is positioned substantially at the outward surface of the first sidewall (16) and/or wherein the tube end surface substantially obstructs a entry opening of the sidewall groove (30) into the first sidewall (16).

8. The tire of at least one of the previous claims, wherein the air tube (34) follows a substantially annular path with the first sidewall (16) and/or wherein the tube cap has a domed outward surface at a radially inward side.

9. The tire of at least one of the previous claims, wherein the inlet housing (92) comprises pressure regulating valve means for controlling pressurized air flow from the tube internal air passageway (34) into the tire cavity (28).

10. The tire of at least one of the previous claims, wherein the inlet conduit (66) connects in air flow communication with first and second opposite ends of the tube internal air passageway (34).

11. A method of assembling a peristaltic air pumping mechanism (14) into a tire (12), the method comprising:

affixing an air inlet housing (92) to an inner liner (26) of a tire (12) having first and second sidewalls (16, 18) extending to a tire tread region (24), the inner liner (26) defining a tire cavity (28);

forming an elongate sidewall groove (30) within the first sidewall (16);

placing an elongate air tube (34) within the sidewall groove (30), the air tube (34) having an internal air passageway (32), wherein the air tube is located within the first sidewall (16) to compress segment by segment from an expanded diameter to a substantially reduced diameter responsive to a bending strain introduced into the first sidewall (16) from a rolling tire footprint whereby forcing air segment by segment along the air tube internal air passageway (32);

configuring the air tube (34) to have a substantially on-side mushroom-shaped sectional profile, the air tube (34) extending radially into the first tire sidewall (16), the air tube (34) having a radially inward cap of relatively larger diametric dimension affixed to a radially outward tube stem of relatively smaller diametric dimension, the inward tube cap residing within an a relatively larger diametric region of the sidewall groove (30) and extending in a lateral outward direction from the tube stem in an orientation substantially parallel with an outward surface of the first sidewall (16); and

configuring the tube stem to have a tapering sectional profile defined by converging sides extending in a radial direction outward from the tube cap to a radially outward stem end surface.

12. The method of claim 11, further comprising configuring the air tube internal air passageway (32) to have a substantially elliptical configuration in transverse section, the elliptical configuration having a longitudinal axis extending radially and a transverse axis extending substantially parallel to the outward surface of the first sidewall (16).

13. The method of claim 11 or 12, further comprising positioning the air tube internal air passageway (32) within the air tube substantially at an intersection of the tube cap and the tube stem; and/or further comprising positioning the tube end surface substantially at the outward surface of the first sidewall (16) to substantially obstruct a entry opening of the sidewall groove (30) into the first sidewall (16).

14. The method of at least one of the claims 11 to 13, further comprising:

extending an elongate tubular inlet conduit (66) between the air tube and the inlet housing, the inlet conduit (66) having an internal air passageway (68) operative to route inlet air from within the inlet housing (92) to the air tube internal air passageway (32); and/or

extending an air intake conduit (76) through the first sidewall (16) to the inner liner (26), the air intake conduit being coupled to the air inlet housing (92) and operative to route air from outside the tire through the first sidewall (16) and into the air inlet housing (92).

15. The method of at least one of the claims 11 to 14, further comprising:

engaging the inlet conduit (66) and the air intake conduit (76) into respective first and second elongate sockets formed by the inlet housing (92), whereby establishing respective air flow communication into the inlet housing; and/or

housing pressure regulating valve means within the inlet housing (92) for controlling pressurized air flow from the tube internal air passageway (32) into the tire cavity (28).

Drawing